Performance difference between servers

We have 3 different servers, one (the oldest) ist significantly faster at
certain operations and I can't find out the reason:

(table created in monospace font)

Server Processor RAM CrystalDiskMark pgbench CREATE DATABASE OS

#1 i7-2600 8GB 495 / 473 26.000 4.5 . 6 s W/
Server 2008 R2 on Hyper V Server 2008

#2 E3-1245 16GB 797 / 514 50.000 13 . 19 s W/
Server 2016 Std. on Hyper V Server 2016

#3 E3-1270 12GB 933 / 334 40.000 13 . 20 s W/
Server 2008 Essentials on Hyper V Server 2016

CrystalDiskMark: "Seq Q32T1"

Pgbench:

pgbench -i -s 200 -U postgres pgbench

pgbench -c 40 -j 10 -T 150 -U postgres -S -P 5 pgbench

CREATE DATABASE:

create database test with template myTemplate

All running PostgreSQL 9.6 x64 with similar configuration. All running as
virtual machines, no other virtual machines creating any load. Using the
same template database on all machines.

Although the indicative numbers of pgbench and CrystalDiskMark show better
values for server #2 and #3, server #1 creates a new database considerably
faster.

All servers have SSDs. Server #1 has two single SSDs (a system disk and a
data disk). Servers #2 and #3 have only one logical disk for system and
data, and this is two SSDs running as RAID 1. This may be slower but if it
is, I would excpect this also to show up in the pgbench results.

The reason behind this exercise is that a test application was also reported
to be slower on server #2 and 3.

Any idea how to track down the performance difference?

Thank you

Klaus